Five years have passed since Hiccup and Raya brought peace to Kumandra and recognised feelings for each other. But their happy life with Toothless, Sisu and their friends is interrupted by the invasion of Hiccup's former clan and all their allies who seek to destroy dragons forever. Together they must battle their foes and Hiccup must face the past he left behind.
Hiccup and his dragon Toothless ran away from Berk and found a group known as Dragon Hunters. They managed to hurt their business without being found or hurt themselves for a while, but their work got the attention of their leader, Krogan, who set off to stop them. During one of their fights, they found Kumandra and ran into a princess named Raya who's trying to save the world.